Give Cedar Lake south of Carbondale a try. It's probably the most scenic lake in Illinois. You can tent camp in the Shawnee Natl Forest. There is a 10 h.p. limit so no jet ski's or hordes of bassboats here.
Little Grassy Lake is also a 10 h.p. limit lake with a campground right on the lake. The fishing is a little tougher at little grassy because the water is so clear.